p.1 #1 · Stop Down Metering with Olympus Lenses -- Different from Zeiss?
On the Cameraquest website, it is stated that the Olympus OM lenses have built in stop down metering. So as I understand it, if you set an Olympus OM f2.0 lens at f11, it will appear through your finder as if it is still at f2.0, and then to meter correctly you just hit a button on the lens right before taking the picture? Is this correct? If so, the OM lenses would appear to be the easiest to use on Canon bodies, right? Surprised I haven't read this anywhere else . . .
p.1 #2 · Stop Down Metering with Olympus Lenses -- Different from Zeiss?
That is correct. I have an OM-EOS adapter coming my way next week. I'll finally get to use some of the Zuikos I have.
The only downside to it that I can think of, are long exposures. You would have to hold the stop-down button for the whole exposure. This would most certainly ruin the shot.. And your hands.
You could always jam the lever on the rear side with, say, a strip of bendy plastic. Possibly with some tape over it to prevent it from falling off. This procedure would, of course, turn the lens into a stop-down operated one.
p.1 #3 · Stop Down Metering with Olympus Lenses -- Different from Zeiss?
Actually, most (all?) OM-EOS adapters have the stop-down button more or less permanently engaged, so they operate the same way other legacy/MF lenses work -- focus with the lens wide open, then turn the aperture ring before releasing the shutter. The reason (as I understand it) is that on a non-OM body, there is no way to set the stop-down button to stay engaged -- you have to hold it in for as long as you want the lens to be stopped down. As the cameraquest site explains, you would have to remove a screw to operate the adapter in the way you describe. I tried it for a while with my (non-Cameraquest) adapter, and found it a bit too fiddly with my 20D, as the lens stop-down button is fairly close to the camera body & hard to reach. Also, as Lasse suggests, this is not feasible when using a tripod & remote shutter release. However, for handheld shots it would work better (subject to the useability caveat above). I will be getting a cameraquest adapter soon, and I may try having one adapter set up each way, as I too like the idea of being able to switch quickly between wide-open for focusing purposes & stopped down for exposure. But the fact is it's not too complicated to just turn the aperture ring on the lens after focusing. The stop detents are easy to feel, and the ring is where it should be (out in front of the focusing ring, unlike the Zeiss lenses I've seen, which have the aperture ring between the focus ring & the body).
p.1 #4 · Stop Down Metering with Olympus Lenses -- Different from Zeiss?
Oh. Thanks for clearing that up.
The adapter I used last week was not mine, but a friend's. He probably had removed the said screw as he isn't really into long exposures anyway.
p.1 #5 · Stop Down Metering with Olympus Lenses -- Different from Zeiss?
For reference, I'm posting this link, which has a clearer explanation than what I was able to offer, as well as a clarification about using the Zuiko shift lenses this way: older thread
